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programming languages Online Quiz - 297

Description: programming languages Online Quiz - 297
Number of Questions: 20
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Tags: programming languages
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Click the Exhibit button. 10. interface Foo { 11. int bar(); 12. } 13. 14. public class Beta { 15. 16. class A implements Foo { 17. public int bar() { return 1; } 18. } 19. 20. public int fubar( Foo foo) { return foo.bar(); } 21. 22. public void testFoo() { 23. 24. class A implements Foo { 25. public int bar() { return 2; } 26. } 27. 28. System.out.println( fubar( new A())); 29. } 30. 31. public static void main( String[] argv) { 32. new Beta().testFoo(); 33. } 34. } Which three statements are true? (Choose three.)

  1. The code compiles and the output is 2

  2. If lines 16, 17 and 18 were removed, the code would compile and

  3. If lines 24, 25 and 26 were removed, the code would compile and the output would be 1

  4. D. If lines 24, 25 and 26 were removed, compilation would fail


Correct Option: A,B,C

Given: 10. interface Foo { int bar(); } 11. public class Sprite { 12. public int fubar( Foo foo) { return foo.bar(); } 13. public void testFoo() { 14. fubar( 15. // insert code here 16.); 17. } 18. } Which code, inserted at line 15, allows the class Sprite to compile?

  1. Foo { public int bar() { return 1; } }

  2. new Foo { public int bar() { return 1; } }

  3. newFoo() { public int bar(){return 1; } }

  4. new class Foo { public int bar() { return 1; } }


Correct Option: C

Given: 10. class Nav{ 11. public enum Direction { NORTH, SOUTH, EAST, WEST } 12. } 13. public class Sprite{ 14. // insert code here 15. } Which code, inserted at line 14, allows the Sprite class to compile?14

  1. Direction d = NORTH;

  2. Nav.Direction d = NORTH;

  3. Direction d = Direction.NORTH;

  4. Nav.Direction d = Nav.Direction.NORTH;


Correct Option: D

Given: 10. package com.sun.scjp; 11. public class Geodetics { 12. public static final double DIAMETER = 12756.32; // kilometers 13. } Which two correctly access the DIAMETER member of the Geodetics class? (Choose two.)

  1. import com.sun.scjp.Geodetics;public class TerraCarta {public double halfway(){ return Geodetics.DIAMETER/2.0; } }

  2. import static com.sun.scjp.Geodetics;public class TerraCarta {public double halfway() { return DIAMETER/2.0; } }

  3. import static com.sun.scjp.Geodetics. *;public class TerraCarta {public double halfway() { return DIAMETER/2.0; } }

  4. package com.sun.scjp;public class TerraCarta {public double halfway() { return DIAMETER/2.0; } }


Correct Option: A,C
  1. Given: 13. public class Pass { 14. public static void main(String [1 args) { 15. int x 5; 16. Pass p = new Pass(); 17. p.doStuff(x); 18. System.out.print(” main x = “+ x); 19. } 20. 21. void doStuff(int x) { 22. System.out.print(” doStuff x = “+ x++); 23. } 24. } What is the result?
  1. Compilation fails.

  2. An exception is thrown at runtime

  3. doStuffx = 6 main x = 6

  4. doStuffx = 5 main x = 5


Correct Option: D

Given: 23. Object [] myObjects = { 24. new integer(12), 25. new String(”foo”), 26. new integer(5), 27. new Boolean(true) 28. }; 29. Arrays.sort(myObjects); 30. for( int i=0; i

  1. Compilation fails due to an error in line 23.

  2. Compilation fails due to an error in line 29.

  3. A ClassCastException occurs in line 29.

  4. A ClassCastException occurs in line 31.


Correct Option: C

Given: 11. public class Person { 12. private name; 13. public Person(String name) { 14. this.name = name; 15. } 16. public int hashCode() { 17. return 420; 18. } 19. } Which is true?

  1. The time to determine whether a Person object is contained in a HashSet is constant and does NOT depend on the size of the map

  2. Deleting a Person key from a HashMap will delete all map entries for all keys of type Person

  3. Inserting a second Person object into a HashSet will cause the first Person object to be removed as a duplicate.

  4. The time to find the value from HashMap with a Person key depends on the size of the map.


Correct Option: D

Which Man class properly represents the relationship “Man has a best friend who is a Dog”?

  1. class Man { private Dog }

  2. class Man { private BestFriend dog; }

  3. class Man { private Dog bestFriend; }

  4. class Man implements Dog { }


Correct Option: C

Assume that country is set for each class. Given: 10. public class Money { 11. private String country, name; 12. public getCountry() { return country; } 13.} and: 24. class Yen extends Money { 25. public String getCountry() { return super.country; } 26. } 27. 28. class Euro extends Money { 29. public String getCountry(String timeZone) { 30. return super.getCountry(); 31. } 32. } Which two are correct? (Choose two.)

  1. Euro returns correct values

  2. An exception is thrown at runtime.

  3. Yen and Euro both return correct values

  4. Compilation fails because of an error at line 25.


Correct Option: A,D

Given: 20. public class CreditCard { 21. 22. private String cardlD; 23. private Integer limit; 24. public String ownerName; 25. 26. public void setCardlnformation(String cardlD, 27. String ownerName, 28. Integer limit) { 29. this.cardlD = cardlD; 30. this.ownerName = ownerName; 31. this.limit = limit; 32. } 33. } Which is true?

  1. The class is fully encapsulated

  2. The ownerName variable breaks encapsulation

  3. The cardlD and limit variables break polymorphism

  4. The setCardlnformation method breaks encapsulation


Correct Option: B

Question 6 Given: • d is a valid, non-null Date object • df is a valid, non-null DateFormat object set to the current locale What outputs the current locales country name and the appropriate version of d’s date?

  1. Locale loc = Locale.getLocale();System.out.println(loc.getDisplayCountry()+ “ “+ df.format(d));

  2. Locale bc = Locale.getLocale();System.out.println(loc.getDisplayCountry()+ “ “+ df.setDateFormat(d));

  3. Locale loc = Locale.getDefault();System.out.println(loc.getDisplayCountry()+ “ “+ df.setDateFormat(d));

  4. Locale loc = Locale.getDefault(); System.out.println(loc.getDisplayCountry()+ “ “ + df.format(d));


Correct Option: D

Given: 10. interface Foo {} 11. class Alpha implements Foo { } 12. class Beta extends Alpha {} 13. class Delta extends Beta { 14. public static void main( String[] args) { 15. Beta x = new Beta(); 16. // insert code here 17. } 18. } Which code, inserted at line 16, will cause a java.lang.ClassCastException?

  1. Alpha a = x;

  2. Foo f= (Alpha)x;

  3. Foo f= (Delta)x;

  4. Beta b = (Beta)(Alpha)x;


Correct Option: C

Given: 31. // some code here 32. try { 33. // some code here 34. } catch (SomeException se) { 35. // some code here 36. } finally { 37. // some code here 38. } Under which three circumstances will the code on line 37 be executed? (Choose three.)

  1. The code on line 31 throws an exception

  2. The code on line 33 throws an exception

  3. The code on line 35 throws an exception

  4. The code on line 33 executes successfully


Correct Option: B,C,D

Given: 11. public class Test { 12. public static void main(String [] args) { 13. int x =5; 14. boolean b1 = true; 15. boolean b2 = false; 16. 17.if((x==4) && !b2) 18. System.out.print(”l “); 19. System.out.print(”2 “); 20. if ((b2 = true) && b1) 21. System.out.print(”3 “); 22. } 23. } What is the result?

  1. 2

  2. 2 3

  3. Compilation fails.

  4. 1 2 3


Correct Option: B

Given: 10. public class Bar { 11.static void foo(int...x) { 12. // insert code here 13. } 14. } Which two code fragments, inserted independently at line 12, will allow the class to compile? (Choose two.)

  1. foreach(x) System.out.println(z);

  2. for(int z : x) System.out.println(z);

  3. while( x.hasNext()) System.out.println( x.next());

  4. for( int i=0; i< x.length; i++ ) System.out.println(x[i]);


Correct Option: B,D

Given: 11. public interface Status { 12. /* insert code here */ int MY_VALUE = 10; 13. } Which three are valid on line 12? (Choose three.)

  1. final

  2. public

  3. native

  4. static


Correct Option: A,B,D

Java APIs are libraries of compiled code?

  1. True

  2. False


Correct Option: A

JFC Stands for

  1. Java Foundation Course

  2. Java Fundamental Classes

  3. Java Foundation Classes

  4. None of the above


Correct Option: C

Which is true about applet?

  1. Applet version has main method

  2. GUI components are added explicitly to the Applet

  3. Aplet class is declared private

  4. None of the above


Correct Option: D

Which of the following are true about Constructors?

  1. Member Function

  2. Same name as Class name

  3. Default constructor initializes all non-initialized fields and variables to zero.

  4. Compiler adds an empty constructor, if we do not write our own constructor


Correct Option: A,B,C,D
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